The antigen-binding sites of an antibody molecule are formed from the molecule's variable regions. Why are these regions described as variable?

Which of the following cell types carries out humoral immunity?

Which of the following functions of plasma-cell-secreted antibodies promotes phagocytosis of foreign bacteria?

The proliferation of the B lymphocyte to which a specific antigen binds is referred to as __________.

Once you have been exposed to an antigen, you develop immunity against the same antigen because __________.

The body produces antibodies complementary to foreign antigens. The process by which the body comes up with the correct antibodies to a specific invader is most like __________.

A viral infection in a cell results in __________.

What is the primary difference between the innate and adaptive immune responses?a. The innate immune response does not distinguish between pathogens, while the adaptive immune response does.b. Only the innate immune response is activated by antigens.c. The adaptive immune response generates immunological memory and is more specific than the innate immune response.d. The innate immune response does not kill cells; the adaptive immune response does.

An epitope associates with which part of an antigen receptor or antibody?a. the tailb. the heavy-chain constant regions onlyc. variable regions of a heavy chain and light chain combinedd. the light-chain constant regions only